Lifting-jack



a. RIADAMS.

LIFTING JACK.

APPLICATION FILED DEC-21, I920.

' 1,399,729, Patented 1m. 13, 1921.

I 9 5 I L I 1/ w ZZ 6 m JZ/ZQ/ GEORGE E. ADAMS, I-IILLSBORO, TEXAS.

premise-anon.

Specification of Letters Patent. Patented ee. 13, 1921..

Application filed December 21, 1920. fierial No. team,

To all: whom it may 00mm Be it known that l, Gnonenltdtnnns, a citizen of theUnited States, i'eslcling at Hillsboro; in the county oi Hilland State nally during both. the upward and downward swing of the actuating lever, thus making for quick operation. ih further object is to provide a jaclr in which the raclr member may be raised by a halt oi the actuating lever, so that in places where the lever cannot be swung above a horizontal position, the rack member may be operated. it further teaturejresides n asimple and efficient shifting means whereby the Cl11eC- tion of movement of the rack member is re versed. y

A construetiondesigned to carry out the invention will be hereinafter described together with other features of the invention.

The invention willfbe more readily under stood from a reading of the following specificationand by reference to theaccompanying drawings, in which an example of the invention isshown," and whereln:

"Figure 1 is avertical sectional v ew of a jack constructed in accordance with my invention and showing the actuating lever at the center of its stroke,

Fig. 2 isa cross-sectional line 2-2 of Fig. 1, p D Fig.3 is a detail of the shltt ng device, showing the reversing arms swung apart for elevatingthewrack member, I

Fig. 1 is a view of the same part from the opposite side, Fig. 5 is a sectional detailshowing the parts reversed for lowering the rack member, [Fig.1 6 is a sectional detail of the upper portion of the jack showing the parts in position to elevate said raclr member and showingtheparts in dotted lines after they have been elevated by one stroke of the actnating lever,

detail on the F'g; 7 is a similarview showing the parts in position for lowering the raclr member,

and p a Fig, 8 a perspective view of one of the reversing arms. I

in the drawings the numeral 10 designates a suitable base carrying an upright stand ard 11 which may be cast integral with the base and is provided with vertical guides 12. A rack member 13 is mounted in the guides or the standard and carries a saddle 1 1- at its upper end in which the part to be elevated may be received. The rack bar is rectangular and has internal racks 1 1 on op posite sides extending vertically thereof. Between the center of the standard and its top a transverse pivot bolt 15 is arranged and extends through the central opening of the memberll. The standard is chambered at 11 and is open on each side so as to re ceive the fork or yoke 16 of an actuating lever 17 extending laterally from the stand ard. The y he embraces themember 13 on each .side and extends through one side of the standard but could be extended through both sides to provide means for two persons to simultaneously operate the jacks.

Within the yoke 16 a pair of dogs 18 and 19 respectively; arepivoted on each side of the bolt 15, said dogs being oppositely dirooted and engaging the racks 1 1 on opposite sides of the member 13. llnspreader spring 20 has its ends attached to theintermediate portions of the dog and is supported thereby as is clearly shown in the drawings. It will be seen that when the lever 17 is swung one dog will be carried downward and the other will be carried upward. The teeth of the racks lt are of such length that either dog will travel over onetooth and engage the next during half the downward swing or stroke of the lever 17. By this arrangement if the lever -17 can be swung only from its lowermost position to its central position, the member 13 will be elevated the distance oi? one tooth as will be obvious. This could not be accomplished with a single acting construction.

Each dog has a transverse pin 21 which has a roller 92 rotatably confined on its outer end. The roller ot the dog 18 cofiperates with a swinging reversing arm 23, while the roller of the dog 19 coiiperates with a swinging reversing arm 24. The arms are pivoted at theirupper ends to the outer side of the standard 11 and have their lower ends connected by a coiled spring 25. Aspreader 26 is pivoted to the standard 11 between the arms and is provided with a reversing bar 27 extending upwardly to a slot 28 in the housing 29 on the side of the standard and in which the arms and spreader are inclosed. When the arms are engaged by the concentric edges of the spreader as is shown in F igs.

3 and 4, said arms are spread apart and the spring is under tension. The spreader has converging faces 26. By swinging the bar 27 to the opposite end of the slot 28 the spreader 26 is rotated so as to bring the faces 26 between the arms so that the latter are swung into contact with said faces and drawn together by means of the spring 25 as is shown in F ig. 5.

,The arm 23 has an inclined guide flange 23, while the arm 24 has an inclined flange 24, said flanges being directed oppositely. The lower flanged ends of the arms engage the roller 22 through slots 29-in one side through the side of the standard 11. It will be seen thatwhen the arms are spread apart the dogs; will be in engagement with the teeth let and the flangesof the arms will be held out of the path of either of the rollers 22. Thus 1 as the lever 17 is swung downwardly the dog 18 will be carried downwardly over the teeth of its rack, while the dog 19 will remain in contact with the teeth of its rack and elevate the member 13. During this downward movement of the lever 17, the dog 18 will slip over two teeth,one during each half of the swing or stroke of said lever. When the lever 17 is swung upwardly the dog 18 will remain in contact with its rack, while the dog 19 will slip over the teeth of its rack.

In this manner the rack member 13 will be quickly elevated.

When it is desired to lower the member 1 18, the bar 27 is swung so as to shift the 7 parts and reverse the operation. The arms will be brought toward each other by the spring 25 and occupy the position shown in ltig. 5. When the lever. 17 is at either end of its stroke one of the rollers 22 will be engaged by'the lower end of its respective arm and held out of engagement with its rack 14; while the roller 22 of the other dog will be above and over the inclined flange of its respective arm- Referring to Fig. 5, it will be seen that the roller-22'of the dog 19 is in engagementwith the lower end of the arm 24, while the .roller of'the dog 18 is above the flange 2 3. Thelever 17 is in its uppermost position as'is shown in Fig. 7. With the a parts in this position the dog 18 is, support- 18 comes into engagement with the flange 23 ing themember 13, and thedog-19 is out of engagement'with its rack. When the lever 17 is swung downwardly the roller of the dog and rides down the same; while the roller of thedog 19 after traveling a short distance up-the arm 24 rides onto the flange 2 1. From this it will be seen that the dog 18 will the load. When the parts are in the position shown in full lines in Fig. 7. the tension of the spring 25 will overcome the spreading action of the spring 20; however when the lever 17 reaches the end of its stroke the spreader spring 20 will assume the position shown in dotted lines, whereby the dog 18 willbe withdrawn and the dog 19 drawn into its rack. Until the sprin 25 overcomes the action of the spring 20, tie dog 18 will remain in engagement with its rack 14. WVhen the lever 17 is thrown upwardly the action is reversed as will be clearly understood. Each dog is moved the distance of two teeth on its rack bar at each stroke, so that a half stroke will move it one tooth and permit the operation of the jack as is apparent.

It is obvious that changes may be made .in the arrangement and dimensions without departing from the spirit of the invention and all such changes and modifications which come within its scope are included.

What I claim is:

1. In a double acting jack, a standard, a rack-member slidably engaging the standard and having a longitudinal opening and spaced longitudinal racks upon opposite sides of said opening, an actuating lever pivoted upon the standard at a point near the longitudinal opening of the rack-member, dogs mounted within the longitudinal opening of the rack-member and pivotally connected with the lever upon opposite sides of its pivot and-arranged to engage the racks, a spring connecting the dogs and serving to shift them outwardly into engagement with said racks, a pair-of retracting arms pivotally connected with the standard upon opposite sides of the pivot of the lever and provided with inclined flanges, lateral extensions carried by the dogs to engage the inclined flanges, a spring connecting the retracting arms'to move them inwardly, and a movable member arranged between the retracting arms and contacting therewith and adapted to shift them outwardly.

2. In a double acting jack, a standard, a rack-member slidably engaging the standard and having a longitudinal opening and spaced longitudinal racks upon opposite sides of said opening, an actuating lever pivoted upon the standard at a point near the longitudinal opening of the rackmember, dogs mounted within the longitudinal opening of the rack-member and pivotally connected with the lever upon opposite sides of its pivot and arranged to engage the racks, a spring con- Cir necting the dogs and serving-to shift them ard and arranged between the retracting arms and adapted to swing them outwardly, and a manually operated element to move the pivoted spreading element.

3, In a double acting jack, a standard, a rack member movable vertically of the standard, an actuating lever pivoted on the standard, dogs carried by the lever on opposite sides of its pivot point and engaging the aclr member, a spreader spring disposed between the dogs and connected there-- with, retracting arms pivoted on the standard, a spring to move the retracting arms inwardly toward each other, the dogs having portions adapted to engage the arms for retracting the dogs from the racks of the movable member, and means for moving the arms out of operative relation to the dogs.

4t. In a double acting jack, a standard, a rack member movable vertically of the standard, an actuating lever pivoted on the standard, dogs carried by the lever on opposite sides of its pivot point and engaging the raclr member, a spreader spring disposed between the dogs and connected therewith, retracting arms pivoted on the standard, the dogs having portions adapted to engage the arms for retracting the dogs trom the racks of the movable member, a spring connecting the retracting arms to move them inwardly toward each other, means for moving the arms out of operative relation to the dogs, and means for releasing the arms to actuate the dogs.

5. ln a double acting jack, a standard, a rack member having internal racks and movable vertically of the standard, an actuating lever pivoted on the standard, dogs pivoted to the lever on opposite sides of its pivot point and engaging the racks of the member, a spreader springhaving its ends connected with the swinging ends of the dogs, rollers carried by the dogs, a pair oi arms pivoted on the standard, a coiled spring connecting the swlnglng ends of the arms, the rollers being disposed between the arms, a spreader arranged between the arms and engaged thereby, and means for springmg the spreader to spread the arms apart.

In testimony whereof I my signature.

GEQJRGE R. ADAMd. 

